This blog features my weekly column called "What's up in the sky". It is published every Saturday in the Ellensburg newspaper, Daily Record (http://www.kvnews.com/). While my postings will be most accurate for Central Washington, readers throughout the northern USA may find something of use.

Monday, December 28, 2015

Saturday: If
the Sun looks big today, your eyes are not playing tricks on you. The Earth is
at perihelion at about 3 p.m., Pacific Standard Time. If you dig out your Greek
language textbook, you’ll see that peri- means “in close proximity” and helios
means “Sun”. So, perihelion is when an object is closest to the Sun in its
orbit, about 1.5 million miles closer than its average distance of 93 million
miles. Since it is winter in the Northern Hemisphere now, the seasonal
temperature changes must not be caused by the Earth getting farther from and
closer to the Sun. Otherwise, we’d have summer when the Earth is closest to the
Sun. The seasons are caused by the angle of the sunlight hitting the Earth. In
the winter, sunlight hits the Earth at a very low angle, an angle far from
perpendicular or straight up and down. This means that a given “bundle” of
sunlight is spread out over a large area and does not warm the surface as much
as the same bundle in the summer. For the Northern Hemisphere, that very low
angle occurs in December, January and February.

Sunday: Late
tonight and early morning’s weather forecast: showers. Meteor showers, that is.
The Quadrantid meteor shower peaks late tonight and early tomorrow morning
between midnight and dawn. Meteor showers are named after the constellation
from which the meteors appear to originate. That makes this shower mysterious
because there isn’t any constellation with this name now. The shower was named
after Quadrans Muralis, an obsolete constellation found in some early 19th
century star atlases. These meteors appear to come from a point in the modern
constellation Draco the dragon. This point is about three fists held upright
and at arm’s length above the northeast horizon at 1 a.m. This year, the waning
crescent moon will not obscure the dimmer meteors. Meteors are tiny rocks that
hit the Earth and burn up in the atmosphere. Most meteors are associated with
the path of a comet. This shower consists of the debris from an asteroid
discovered in 2003. Keeping with the comet-origin paradigm, astronomers think
the asteroid is actually an “extinct” comet, a comet that lost all of its ice
as it passed by the Sun during its many orbits. For more information about the Quadrantid
meteor shower, go to http://earthsky.org/?p=4287.

Monday: Jupiter
is a half a fist above due east at 11 p.m.

Tuesday: On
these cold mornings, it is difficult to get going. You just want to plop into a
chair and sit still. But, are you really sitting still? You’re moving at about
700 miles per hour due to the rotation of the Earth on its axis and 66,000
miles per hour due to the revolution of the Earth around the Sun. If that’s not
enough, the entire solar system is orbiting the center of the galaxy at a
whopping 480,000 miles per hour! So while you may be sitting still with respect
to your living room (and all of the over achievers in your house), you are NOT
sitting still with respect to the center of the galaxy. For more information
about this concept, go to http://goo.gl/lPVPS. Before
you barf from all of that motion, go outside at 7 a.m. and observe five Solar
System objects. Bright Venus is one and a half fists above the southeast
horizon. Saturn is about a half a fist to the lower left of Venus. Mars is
three fists above due south. Jupiter is three and a half fists above the
southwest horizon. And, of course, I bet you spotted the moon while you were
finding the other objects. Speaking of motion, because of Saturn’s rapid
rotation, only 10.5 hours, it appears visible flattened.

Wednesday:
Has it been tough to wake up this past week? It should have been because the
sunrise has been getting a little later since summer started. I know. I know.
December 21 was the shortest day of the year. But, because the Earth’s orbit
around the Sun is elliptical and not circular, the Earth does not travel at a
constant speed. It moves faster when it is closer to the Sun and slower when it
is farther away. This leads to the latest sunrise occurring around the first of
January and the earliest sunset occurring in early December, not on the first
day of winter, the shortest day of the year. On the first day of winter,
however, the interval between sunrise and sunset is the shortest. For more
information, go to http://goo.gl/SJC5r.

Thursday: A
new year leads us to contemplate our future. Let’s take some time to contemplate
the Sun’s future. The Sun has spent a few billion years as a stable star fusing
hydrogen into helium. Once that easily fusible hydrogen is gone, the Sun’s
outer layer will puff up like a hot air balloon, getting larger, cooler, and
redder. The star Aldebaran, in the constellation Taurus looks like what our Sun
will look like in a few billion years. Read more about Aldebaran and the Sun’s
future at https://stardate.org/radio/program/moon-and-aldebaran-25. At 9:30
p.m., Aldebaran is almost exactly 60 degrees, or six fists, above due south.

Friday:
Have you ever looked down on the ground and spotted a penny? In Yakima? While
you were standing in Ellensburg? If you have, then you may be able to see the
star Hamal as more than just a point of light. It has an angular diameter that
can be directly measured from Earth. Hamal, the brightest star in the
constellation Aries the ram, has the same angular diameter as a penny 37 miles
away. (For comparison, the moon is about half the diameter of a penny held at
arm’s length.) Hamal is three and a half fists above due west at 11 p.m.

The
positional information in this column about stars and planets is typically
accurate for the entire week. For up to date information about the night sky,
go to http://nightsky.jpl.nasa.gov/planner.cfm.

Wednesday, December 23, 2015

Saturday: When
the Moon is full or close to full, it is difficult to see dim objects in the
sky because of the sky glow. But why struggle to find dim objects when there is
so much to see on the big, bright object in front of you? The lunar crater
called Tycho is best seen during a full Moon. Tycho was formed about 109 million
years ago when an asteroid struck the Moon, leaving a crater over 50 miles in
diameter and ejected dust trails that radiate out hundreds of miles in all
directions. For more lunar highlights, go to
http://nightsky.jpl.nasa.gov/docs/ObserveMoon.pdf, a resource of the Night Sky
Network.

Sunday: You’ve
heard the term “a pinch to grow an inch.” Well, Jupiter’s extremely strong
gravitational field “pinches” Jupiter so much that it causes Jupiter to shrink
by about an inch a year. Look for the svelte Jupiter one fist held upright and
at arm’s length above due east at midnight.

Monday: You’ve
heard the term “a pinch to grow an inch.” Come on. Now I know you have. While
there is no pinching involved, the distance between the Earth and moon
increases by about an inch a year. Does it look farther tonight than when you
looked at it on Saturday? It’s 2/365ths of an inch farther from the Earth.

Tuesday:
Hit the road Mercury. And don’t you come back no more, no more. For a few
weeks, Mercury has been hitting the road and moving away from the Sun in the
sky. Today, Mercury is as far away from the Sun as it will get on the evening
half of this cycle. This is known as its greatest eastern elongation. Yet, this
distance does not translate into good viewing because Mercury will be very low
in the sky. Mercury is about a half a fist above the southwest horizon at 5
p.m. Over the next few weeks, Mercury will move toward the Sun in the sky.
After it passes in front of the Sun, it will appear in the morning sky by the end
of January.

Wednesday:
At 7:30 a.m., Saturn is one fist above due southwest. The much brighter Venus
is a fist to the upper right of Saturn. The reddish planet Mars is about three
fists above the south horizon.

Thursday: Forget
about that big bright ball in Times Square. You can mark the start of the new
year with one of the sky’s own big bright balls. That perennial favorite New
Year’s Day marker, Sirius, the brightest star in the night sky, rises to its
highest point in the sky a little after midnight on January 1. Thus, when
Sirius starts to “fall”, the new year has begun. Look for Sirius about two and
a half fists above due south at midnight.

And
while you are up, grab those binoculars and look for Comet Catalina right next
to the bright star Arcturus throughout the night. Arcturus and Catalina rise in
the east-northeast sky just after midnight. By 3 a.m., they are three fists
above due east. By 6 a.m., they are two and a half fists above the southeast
horizon.

Friday:
Today is the day we celebrate the anniversary of something new – a new
classification of celestial objects. Giuseppe Piazzi discovered Ceres
[pronounced sear’-ease], the first of what are now called “asteroids”, on
January 1, 1801. Ceres is the largest asteroid in the belt between Mars and
Jupiter. At first, Piazzi thought it was a star that didn’t show up on his
charts. But, he noted its position changed with respect to the background stars
from night to night. This indicated to him that it had to be orbiting the Sun.
The International Astronomical Union promoted Ceres to the status of “dwarf
planet” in August of 2006.

The
positional information in this column about stars and planets is typically
accurate for the entire week. For up to date information about the night sky,
go to http://nightsky.jpl.nasa.gov/planner.cfm.

Friday, December 11, 2015

Saturday: Today:
I know you’re staying up late to train yourself to wait up for Santa. So look
out a south-facing window at 1 a.m. and see Sirius, the brightest star in the
nighttime sky, as high as it ever gets in the sky. It is two and a half fists
held upright and at arm’s length above due south.

Sunday: Two
of the best, and certainly the most available, “tools” for viewing the night
sky are your eyes. Your eyes let you see the entire sky in just a few seconds. Your
eyes can read star charts, decipher astronomy apps, and spot meteors while your
friend is still setting up her tripod. Your naked eyes are not as effective as
gathering light. They work well when the light source is comparatively bright
and the detailed features are fairly large. It’s best to practice on a special
Solar System body known scientifically as the Magnificent Optical Object of Nearness.
Artists such as Jan van Eyck and Leonardo da Vinci produced the first realistic
naked eye depictions of the Magnificent Optical Object of Nearness. This week
you can use your own eyes to observe evidence of violent collisions and ancient
lava flows. For more information to observe the Magnificent Optical Object of
Nearness, better known as the Moon, go to http://goo.gl/JLhraO.

Monday: At
8:48 p.m., the Sun reaches its lowest point in the sky with respect to the
background stars. This point is called the Winter Solstice. During the day that
the Sun reaches this point, your noontime shadow is longer than any other day
of the year. Also, the Sun spends less time in the sky on the day of the Winter
Solstice than any other day making this the shortest day of the year. Even
though it is the shortest day of the year, it is not the day with the latest
sunrise or the earliest sunset. The latest sunrise is during the first week in
January and the earliest sunset is during the second week in December. The Sun
is at its southernmost point with respect to the background stars on the day of
the winter solstice. This means the Sun spends the least amount of time above
the horizon on that day. But, the Sun rise and set time depends on more than
its apparent vertical motion. It also depends on where the Sun is on the
analemma, that skinny figure-8 you see on globes and world maps. During the
second week in December, the Sun is not quite to the bottom of the analemma.But, it is on the first part of the
analemma to go below the horizon. During the first week in January, it is on
the last part of the analemma to rise above the horizon. For more information
on this, go to http://goo.gl/KpbkTf.

Tuesday: At
7 a.m., bright Venus is two fists above the southeast horizon, Mars is three
and a half fists above the south horizon, and Jupiter is more than four fists
above the south-southwest horizon.

Wednesday:
What would that special someone want to see on the back of Santa’s sleigh when
she gets up early Christmas morning to eat one of Santa’s cookies? A fruit
cake? No. A barbell? Maybe to work off the fruitcake. A subscription to The
Daily Record? Of course. But what she really wants is a ring. And if she looks
out a south-facing window, she’ll see her ring. Saturn the ringed planet, that
is. Saturn is about a half a fist above the southeast horizon at 7 a.m.

Thursday: Tonight’s
late night full moon is in the constellation Orion. Tonight’s other Moon is….
Wait a minute. The Earth has only one Moon. True. And it has always had only
one Moon. Not necessarily true. According to the best existing model, about
four billion years ago, a Mars-sized object collided with the young Earth. The
resulting debris coalesced to form the Moon. However, this model left a
mystery: why is the Moon so asymmetric? Hardened-lava lowlands dominate the
near side while the far side is dominated by mountainous highlands. According
to a recent revision of the prevailing model, the early collision formed a
large Moon and a small Moon. Over the years, the small Moon caught up to and
collided with the large Moon. The highlands are the material from the collided
small Moon. For more information about this theory, go to http://goo.gl/O801zk.

Friday: Where
is the one who has been born King of the Jews? We saw Jupiter being eclipsed by
the Moon in the east and have come to worship him” (Matthew 2:2, Bruce
Palmquist version, informed by Michael Molnar). There are many theories as to
the physical explanation of the Star of Bethlehem, the celestial object that
guided the wise men to the location of Jesus. Some people think it was a
recurring nova, a star that explodes. Some think it was a close alignment of
bright planets. Some think it was a miracle that requires no physical
explanation. In 1991, astronomer Michael Molnar bought an ancient Roman Empire
coin that depicted a ram looking back at a star. Aries the ram was a symbol for
Judea, the birthplace of Jesus. The Magi, or “wise men”, who visited the baby
Jesus practiced astrology and would have been looking in that region of the sky
for the king prophesied in the Old Testament. Molnar, a modern day wise person,
used sky simulation software to model the positions of planets and the Moon in
the region of Aries. According to his model, Jupiter was eclipsed, or blocked,
by the Moon on the morning of April 17, 6 BC. A book written by the astrologer
of Constantine the Great in 334 AD supports Molnar’s theory. The book describes
an eclipse of Jupiter in Aries and notes a man of divine nature born during
this time. See http://www.eclipse.net/~molnar/ for more information.

The moon,
Aries, and Jupiter make an appearance in the Christmas sky tonight. The moon rises
a little after 5 pm. At 8 p.m., the dim constellation Aries is six and a half fists
above due south. Jupiter is about one above the east horizon just before
midnight.

The
positional information in this column about stars and planets is typically
accurate for the entire week. For up to date information about the night sky,
go to http://nightsky.jpl.nasa.gov/planner.cfm.

Saturday: Columbia
the dove, representing the bird Noah sent out to look for dry land as the floodwaters
receded, is perched just above the ridge south of Ellensburg. Its brightest
star Phact is about one fist held upright and at arm’s length above the south
horizon at midnight.

Sunday: The
Geminid meteor shower peaks for the next two nights. Meteor showers are named
after the constellation from which the meteors appear to originate. These
meteors appear to come from a point in Gemini the twins. This point is about
three fists above the east-northeast horizon at 9 p.m. tonight. You can follow
this point throughout the night, as it will remain near the bright star Castor,
the right hand star of the “twin” stars Pollux and Castor. This shower is
typically one of the best ones of the year producing bright, medium speed
meteors with up to 80 meteors per hour near the peak. This year, the waxing
crescent moon will set before the peak viewing time.

Most
meteor showers occur when the Earth passes through the orbital trail of a comet.
The broken off comet fragments collide with the Earth and burn up in the
atmosphere. Astronomers had searched for a comet source for this shower since
1862 when the shower was first observed. Finally, in 1983, astronomers
discovered the object that created the fragments that cause the meteor shower.
To their surprise, it was a dark, rock that looked like an asteroid, not a
shiny icy comet. Astronomers named this object Asteroid 3200 Phaethon. But,
they still don’t know if it an asteroid or if it is a comet with all of its ice
sublimated away by many close passes by the Sun. For more information about the
Geminid shower, go to http://earthsky.org/space/everything-you-need-to-know-geminid-meteor-shower. Now
that’s a self-explanatory URL!

Monday: Just
before Christmas, you look for junk to clean out of your closets so you can
re-gift it. I mean, so you can throw it out or recycle it. NASA’s Meter Class
Autonomous Telescope on Ascension Island is a key tool in a program tracking about
22,000 pieces space junk. Some of this junk is dangerous. The International
Space Station occasionally performs debris avoidance maneuvers to keep is
panels and sensitive instrument safe. For more information about the project,
go to http://goo.gl/Kxgihd.

Tuesday:
At 7 a.m., bright Venus is two fists above the southeast horizon, Mars is three
and a half fists above the south-southeast horizon, and Jupiter is four and a
half fists above the south-southwest horizon.

Wednesday:
“Lately, I’ve been, I’ve been losing sleep. Dreaming about the things that we
could be. But baby, I’ve been, I’ve been praying hard, said no more counting
dollars. We’ll be counting 9,096 stars, yeah we’ll be counting 9,096 stars.”
Luckily, artistic judgment prevailed over scientific precision in the OneRepublic
hit “Counting Stars”. According to the Yale Bright Star Catalog, there are
9,096 stars visible to the naked eye across the entire sky if you are observing
from a very dark site. In the northern United States, where a part of the sky
is never visible, that number drops to about 6,500. In the middle of a small
city at mid-latitudes, like Ellensburg, that number drops to a few hundred. No
wonder someone has been losing sleep. Learn more about the star count at http://goo.gl/nt8d80.

Thursday: Today
is Saturnalia, an ancient Roman festival in honor of their god Saturn, the god
of agriculture and time. The holiday featured a break from work and school, a
public banquet, and private gift giving. Some of these customs influenced the
secular aspects of Christmas celebrations. Celebrate Saturnalia at 7 a.m. by
viewing the planet Saturn, a half a fist above the southeast horizon. Seeing
the real Saturn on the morning of December 17? As Leonard said on The Big
Bang Theory, “It’s a Saturnalia miracle.”

Friday: This
is a great time of the year to go around and observe the holiday lights… from
SPACE. A NASA satellite has been tracking the spread of Christmas lighting for
the past three years. In that time, lights around major US cities shine 20 to
50 percent brighter from Thanksgiving to New Years Day than they do the rest of
the year. That makes power companies very happy. Some of the NASA images are
available at http://goo.gl/X8Vvuz.

The
positional information in this column about stars and planets is typically
accurate for the entire week. For up to date information about the night sky,
go to http://nightsky.jpl.nasa.gov/planner.cfm.

Thursday, December 3, 2015

Saturday: The
earliest sunset of the year occurs throughout the next week: 4:13 p.m. This
seems odd because the shortest day of the year, the winter solstice, isn’t for
about two more weeks. The Sun is at its southernmost point with respect to the
background stars on the day of the winter solstice. This means the Sun spends
the least amount of time above the horizon on that day. But, the sunrise and
sunset times depend on more than its apparent southward motion in the sky. It
also depends on where the Sun is on the analemma, that skinny figure-8 you see
on globes and world maps. During the second week in December, the Sun is not
quite to the bottom of the analemma. But, it is on the leading edge of the
analemma, the first section to go below the horizon. For a slightly different
explanation about this, go to http://goo.gl/kjnHP. Or just
go watch the sunset. But don’t stare at the Sun.

Sunday: The
Oort cloud object called Comet Catalina has made its way into the morning sky
for northern observers. Early estimations called for it to be visible with the
naked eye comet but recent measurements rate it as a 6th magnitude object. This
makes binoculars a necessity. For this morning and the next few mornings, look
for Comet Catalina about a half a fist to the left of Venus. First find Venus,
the brightest point of light in the sky, two fists held upright and at arm’s
length above the southeast horizon. Aim your binoculars so Venus is in the
right hand portion of your binocular field of view. Comet Catalina will be on
the left hand side of the field of view. For more information about viewing
Comet Catalina, go to http://goo.gl/9b4F23.

Monday: Yesterday
I suggested you use binoculars to find Comet Catalina. You may have scoffed,
thinking only the purity of the naked eye or the glory of a telescope are the ideal
routes to astronomy enjoyment. Oh no. Binoculars are a great tool observing the
sky. They are small, relatively inexpensive, and easy to use. After looking for
Comet Catalina this morning, move your binoculars westward to look at the Moon.
You’ll see a few craters on the lit side and a few long shadows along the
light-dark border called the terminator. For more information about using
binoculars, go to http://goo.gl/xWwYkb.

Tuesday:
Do you look into a nursery and say, “it’s a boy” or “it’s a girl”? Not me. I
say, “It’s a star”. Of course, I like looking into a stellar nursery – a
star-forming region such as the Orion Nebula in the middle of Orion’s sword
holder. The Orion Nebula looks like a fuzzy patch to the naked eye. Binoculars
reveal a nebula, or region of gas and dust, that is 30 light years across. The
center of the nebula contains four hot “baby” stars called the Trapezium. These
hot stars emit the ultraviolet radiation that causes the Nebula’s gas to glow.
The Orion Nebula is three fists above the southeast horizon at 11 p.m.

Wednesday:
Warrant, the American glam metal band (as labeled by Wikipedia) was singing
about carbon stars in its 1991 hit “I Saw Red”. The lyrics for the astronomy
version are “Then I saw red, when I looked up in the sky, I saw red, Orion’s
bright star it was by.” R Leporis, also known as Hind’s Crimson Star, is one of
the reddest stars in the sky. It is a star near the end of its life that has
burned its helium nuclei into carbon. Convective currents, like those in a pot
of boiling water, bring this carbon to the surface. There it forms a layer of
soot that scatters away the light from the blue end of the visible spectrum
leaving the light from the red end of the spectrum to reach our eyes. For more
information about Hind’s Crimson Star and a list of other deep red stars, go to
http://goo.gl/EnhRe4. Hind’s
Crimson star is one fist to the lower right of Rigel, the brightest star in
Orion. You’ll need binoculars or a small telescope to see it Hind’s Crimson
star. But you can easily spot Rigel three fists above the southeast horizon at
10 p.m.

Thursday: You
can see red again this morning, the red planet. Mars is three fists above the
southeast horizon at 6 a.m. Jupiter and its Great Red Spot is four and a half
fists above the south horizon at this time.

Friday: Fomalhaut,
the southernmost bright star visible from Ellensburg, is a little less than one
and a half fists above due south at precisely 5:38 p.m. Set your watch by it.
(“Mommy, what is a watch?”)

The
positional information in this column about stars and planets is typically
accurate for the entire week. For up to date information about the night sky,
go to http://nightsky.jpl.nasa.gov/planner.cfm.